Strong Acid
An acid that ionises essentially completely in aqueous solution.
Formula / equation
HA → H⁺ + A⁻ (complete)
Unit
mol/L
In depth
Because ionisation is complete, the hydrogen ion concentration equals the acid concentration for a monoprotic acid, and pH follows directly. Strong acids are strong electrolytes and are all levelled to the same effective strength in water, since none can be stronger than H₃O⁺.
Examples in the real world
HCl, HBr, HI, HNO₃, H₂SO₄ (first proton) and HClO₄.